All 12 bearings (I bought 2 packs) are approved (most of them are 8.00mm+-0.05mm ID). I bought these to replace the IGUS bushings on my Anet A8 and they do a great job with no play. Note: Apparently I didn't read the fine print that IGUS bushings can be corroded by some lubes, but that's user error, not the fault of the product.